Obsessive-compulsive disorder (OCD) is characterized by recurrent and persistent thoughts, impulses or images (obsessions) and/or repetitive behaviors or mental acts that the person feels driven to perform (compulsions), e.g. doubting, checking and washing. The lifetime prevalence of OCD is 1-3% in the general population. Like many psychiatric disorders, OCD is likely a heterogeneous disorder comprised of several subtypes with distinct genetic and environmental risk factors and pathophysiological mechanisms.
The first line therapy of OCD includes selective serotonin reuptake inhibitors (SSRI), such as escitalopram, fluvoxamine, fluoxetine, paroxetine, and sertraline, as well as clomipramine, a tricyclic antidepressant (TCA), which inhibits serotonin reuptake (Kellner (2010) Dialogues Clin Neurosci. 12:187-197).
However, clomipramine is less well tolerated than the SSRIs. Besides, about 40% to 60% of the patients do not respond sufficiently to oral serotonergic antidepressants. Accordingly, there is a need for other drugs to manage OCD (Kellner (2010) Dialogues Clin Neurosci. 12:187-197).
Stiripentol (Diacomit, 1-penten-3-ol-(1,3-benzodioxol)-4,4-dimethyl or 4-dimethyl-1-[3,4-methylenedioxy-3,4)-phenyl]-1-penten-3-ol) is a racemic allylic alcohol that is structurally unrelated to other antiepileptic drugs.

Stiripentol has shown anticonvulsant activity in several animal models but its spectrum of clinical activity is relatively narrow. The efficacy of Stiripentol, as an add-on therapy to valproate and clobazam, in controlling epilepsy seizures in children presenting with Dravet syndrome, was demonstrated in two randomized, double-blind, placebo-controlled studies. The primary efficacy endpoint for both studies was responder rate. A responder was defined as a patient who experienced a ≥50% decrease in the frequency of generalized clonic or tonic-clonic seizures during the double-blind treatment period compared to baseline (Chiron (2000) Lancet 356:1638). Stiripentol was granted a European Marketing Authorisation for this indication.